Phonograph



April 8, 1924; 1,489,914

E. V. BATEMAN PHONOGRAPH Filed Jul 18. 1922 2 Sheets-Sheet 1 E I/Bafieman Patented Apr. 8, 1924.

UNITEDH ATES 1,489,914 PATENT OFFICE;

v. BATEMAN, or BALLINGER, TEXAS.

rnonoemn;

Application'filed July 18,

provide a soundchamber free of any metallic influences. 1 And the inventlon has as a'still further object to provide a sound chamber of highly resonant qualities and which will be so mounted that the-J vibration of the chamber 1 will be'undam ped.

hereinafter.

In the drawings: V Figure 1 is 'afragmentary vertical sectional view of my improved phonograph particularly showing the mounting of the sound chamber,

Other and incidental objects-will appear Figure 2 is a vertical sectional View showing the sound chamber in'detail,

Figure '8 is a top plan view of the chamber Figure 4 is a transverse. sectional view through the sound chamber on the line 44-.

of Figure 3, looking in the direction of the arrows,

v Figure 5 is an enlarged vertical sectional view particularly showing the throat tube of the sound chamber, and r t Figure 6 is a fragmentary sectional View showing the manner in which the suspension wire of the sound chamber is connected thereto. a Y

In carrying the invention into effect, I employ a cabinet 10 at the upper end of whichis a compartment 11 provided. at the forward side of the cabinet with an opening 12 normally closed by a pair of doors 13. Closing the compartment at its upper side is a motor board 14 above which is arranged a turntable .15 driven by a motor 16 arranged beneath the board, the motor and turntable being conventionally illustrated. Formed through the board near the rear side wall of the cabinet is an opening 17 and secured to the upper face of the board at the upper 1922. Serial No. 575,771.

end of said opening is a base ring, as conventionally illustrated at 18. Ihterposerl between the base ring and the motor board 1s a preferably rubber gasket 18" and rotatably mounted upon thebase ring is a tone arm, as conventionally illustrated at 19.

At its outer end the tone arm carries an appropriate sound box 20 while at its inner end said arm is formed with an elbow 21 rotatably fitting upon the base ring 18. [The base ring is formed :with the usual frusto= conical inner wall 22 at the lower end of which is an annular flange 22 and extending from said wall is a spider 23 from which rises a post 23' extending through the wall of the elbow 21 and rotatably securing the tone arm upon the base ring.

Arranged within the compartment 11 of the cabinet to communicate with the tone arm 19, is a sound chamber comprising top and bottom walls 24 and side walls 25. At

its inner end this chamber is formed with a downwardly and forwardly curved neck 26, the inner terminal of which is square in cross section. However, as clearly shown in Figures 2 and 4, the top and bottom walls of the chamber as well as the side wallsthereof, are gradually widened from the inner terminal of the chamber toward the forward end thereof sothat the chamher is gradually flared from its inner end to its outer end until the mouth of the chamber is reached where said chamber is oblong in cross section.

Each of the walls 24: and 25 of the chamber is preferably formed from a single piece of thin wood having the grain thereof extending longitudinally of the chamber in unbroken continuity from the innerend of the chamberto its mouth. It has been found in practice that the resonance of the chamher is thus materially enhanced and it is now to be observed that the chamber is built up by assembling the walls thereof in the manner shown in Figure 4. As will be noted, the top Wall is arranged to overhang the side walls while the side walls are arranged to overhangthe bottom wall and glued to the, overhanging portions of said walls are wooden cleats 27 fitting in the angles between the walls and securing said walls together, the walls also being glued to each other at the joints therebetween. The cleats, like the walls, are thin and are each formed from a single piece of wood, the grain of the cleats extending longitudinally faces'within the chamber for reflecting the sound waves and glued to the outer faceof each of said walls near the mouth of the chamber is a single thin wooden reinforcing cleat 28. These cleats lie ina plane common thereto and are each. formed from a single piece of straight grained material. Fitting in the mouth of the chamber medially thereof is a vertical strut 29. This strut, like the cleats, is'formed from a thin piece'of straight grained wood and is glued in position, the strut bracing the top and bottom walls of the chamber with respect to each other.

Mounted in the inner end of the sound chamber is a cylindrical throat tube 30 coupling the sound chamber with the tone arm 19. This throat tube, like the sound chamber, is of wood and is turned to provide a block or head 31 at the lower end of the tube while at its upper end the tube is beveled at its exterior to provide a reduced tapered terminal 32', at the base of which is an annular-shoulder 32. The block 31 is shaped to snugly fit in the inner end of the chamber lying flush therewith and is glued to the walls of the chamber for connecting the throat tube therewith and formed in the terminal 32 of the tube is a plurality of spaced longitudinally directed slots 33. As best shown in Figure 5, the tube is of an external diameter to be freely received through the opening 17 in the motor board 14 out of contact therewith so that the sound vibrations within the tube will not be deadened by the board while the tapered upper I terminal 32 of the tube fits within the base commodated in the notches 33 of said terminal. As will be observed, the taperedouter wall of the terminal seats flat against the.

frusto conical inner wall 22 of the base ring while the shoulder 32' of the tube abuts the flange 22 of the base ring. A tightly closed joint is thus formed between the throat tube .and the base ring so that leakageof sound vibrations at this point will be prevented while the vibrations will be directed from the tone arm through the throat tube into the sound chamber without being influenced by the motorboard. Mounted in the lower end of the throat tube'is a conical throat extension tub or amplifier 34: extending downwardly into the neck'26 of the, sound chambration of the plate or bolt.

her. This amplifier is preferably formed of shellacked sheep skin and is glued at its upper end within the lower end of the throat tube while the lower end of said amplifier terminates close to the bottom wall of the neck, the amplifier being straight. This amplifier will tend to add clearncss as well as softness to the sound tones. Connected at its ends to the motor board 14: is a suspension wire 35 extending beneath the neck of the sound chamber supporting said chamber at its inner end and holding the throat tube 30 tightly engaged in the base ring 18 of the tone arm. Mounted upon the top wall of the chamberat its forward margin is, as shown in detail in Figure 6, an angle plate 36 secured by a bolt 37 extending through the wall and preferably, rubber gaskets 88 are employed for overcoming individual vi- Connected at one end to the plate is a wire 39, the opposite end of which is, as shown in Figure 1, connected with the motor board 14 so .that said Wire will thus sustain the forward end of the sound chamber out of contact with the walls of the cabinet in registering relation to the opening 12 in the front wall of the cabinet. Practically undamped vibra tion of the chamber will accordingly be had and, in this connection, it is to be noted that the throat tube 30 will "coact with the arms of the spider 23 to prevent rotation of the tube so that the forward end of the chamber will be held against lateral displacement.

Having thus described the invention, what is claimed as new is:

1. In a phonograph, the combination of a cabinet having a wall thereof provided with an opening, a tone arm mounted upon said wall and including a base ring having a spider therein, and a sound chamber located in the cabinet and provided at its inner end with a throat tube extending through said opening into the ring to communicate with the tone arm,said tube being formed with slots accommodating the arms of the spider.

2. In a phonograph, a'motor board, a tone farm having a base ring mounted on the motor board at its upper side, said ring being provided with a conical bore therethrough, a sound chamber disposed below ing from the inner end ofthe sound chamber through the motor board to project the motor board, and a throat tube extend- 1 a conical exterior face fitting the bore of r the base ring as well as to define a fiat ex-.

terior shoulder at the lower end of said face abutting the lower edge of the ring. 5

In testimony whereof I afiix my signature.

, EARL v. LBATEMAN. [Ls] 

